Table 1 Reasons for not participating in a therapeutic clinical trials by domain and ethical factors

Patient-trial fit

Scientific oversight [10, 53]

Institution

5-Independent review

Beneficence

Cannot identify patients

Patients seek services elsewhere

2-Scientific validity

Cannot enroll enough patients

Unavailability

No measureable/confirmable disease

Availability by disease characteristics [1, 20]

1-Social value

Justice

No testable treatments for the disease, stage, or other characteristics

Investigators

Eligibility [9]

3-Fair subject selection justice

Prior tumor, second cancer, metastases

Precluded by prior or current treatment or co-morbid conditions

Beneficence

Poor performance status

Asymptomatic

Study demands

Physician triage [25]

Physician

4-Favorable risk-benefit ratio

Treatment not tolerated, died soon, disease is too advanced

Quality of life issues

Life expectancy is limited

Need for immediate treatment

Physician preference/judgment

Opportunity

Discussion of trials [27, 33, 36, 37]

Physician

6-Informed and voluntary consent

Respect for persons

Physician judged compliance issues

Doctor-patient communication issues

Interest and willingness [24, 29, 30, 39]

Patient

6-Informed and voluntary consent

Respect for persons

Treatment preference /placebo

Minimal care: symptomatic treatment only, supportive or hospice care desired, refused further staging

Not interested

Barriers: distant from clinic [5], financial, insurance [48], personal circumstances

Second opinion only, return to home physician, no ongoing relationship

Acceptance

Patient consent [45]

Patient

6-Informed and voluntary consent

Respect for persons

Fear of randomization

Fear of side effects

Negative aspects of a trial participation, distance

Patient enrollment

Investigator

7-Respect for enrolled subjects

Patient failed trial screening protocol

Withdrawal